Effect of dietary trace mineral concentration and source (inorganic vs. chelated) on
performance, mineral status, and fecal mineral excretion in pigs from weaning
through finishing
B. L. Creech, J. W. Spears, W. L. Flowers, G. M. Hill, K. E. Lloyd, T. A. Armstrong and T.
E. Engle
J Anim Sci 2004. 82:2140-2147.
The online version of this article, along with updated information and services, is located on
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Effect of dietary trace mineral concentration and source (inorganic vs. chelated)
on performance, mineral status, and fecal mineral excretion in pigs
from weaning through finishing1,2
B. L. Creech*, J. W. Spears*3, W. L. Flowers*, G. M. Hill†, K. E. Lloyd*,
T. A. Armstrong*4, and T. E. Engle*5
*Department of Animal Science, North Carolina State University, Raleigh 27695-7621; and
†Department of Animal Science, Michigan State University, East Lansing 48824-1225
ABSTRACT:
Two hundred and sixteen weanling
gilts (6.65 ± 0.08 kg) were used to determine the effects
of decreasing supplemental concentrations of Zn, Cu,
Fe, and Mn, and trace mineral source (inorganic vs.
chelated) on growth performance, mineral status, and
fecal mineral concentrations from weaning through development. The study was conducted over three trials
with 72 pigs in each trial. Gilts were blocked by weight
and randomly assigned to either 1) control, 2) reduced
inorganic, or 3) reduced chelated trace minerals. The
control diet was supplemented with 25, 150, 180, and
60 mg/kg of Cu, Zn, Fe, and Mn (in sulfate forms),
respectively, during the nursery phase and 15, 100, 100,
and 40 mg/kg of supplemental Cu, Zn, Fe, and Mn,
respectively, during the growing and gilt-developer
phases. Reduced inorganic and reduced chelated treatments were supplemented during all phases with 5, 25,
25, and 10 mg/kg of Cu, Zn, Fe, and Mn, respectively.
The reduced chelated treatment supplied 50% of the
supplemental Cu, Zn, Fe, and Mn in the form of metal
proteinates, with the remainder from sulfate forms.
Performance by control pigs did not differ from pigs
fed the reduced trace mineral treatments during the
nursery and grower-development periods. Gain:feed
was lower (P < 0.05) for pigs fed the reduced inorganic
compared with those fed the reduced chelated treatment during the nursery period. Trace mineral source
did not affect performance during the growing or giltdeveloper phase. Plasma Zn concentration and alkaline
phosphatase activity were higher (P < 0.01) in control
pigs than in those receiving reduced trace minerals
during the nursery and growing phases. Plasma Cu
concentration and ceruloplasmin activity were generally not affected by treatment. Hemoglobin concentrations were lower (P < 0.05) for the reduced inorganic
compared with the reduced chelated treatment in the
nursery phase. Fecal concentrations of Cu, Zn, and Mn
were lower (P < 0.05) in pigs fed reduced trace minerals
than in controls during all production phases. Fecal Zn
concentration during the nursery and fecal Cu concentrations during the growing and gilt-developer phases
were lower (P < 0.05) in pigs fed the reduced chelated
compared with the reduced inorganic treatment. Results indicate that reducing the concentrations of Zn,
Cu, Mn, and Fe typically supplemented to pig diets
will greatly decrease fecal mineral excretion without
negatively affecting pig performance from weaning
through development.
Key Words: Copper, Pigs, Zinc
2004 American Society of Animal Science. All rights reserved.
Introduction
Long-term application of swine lagoon effluent
(Mueller et al., 1994) and broiler litter (Kingery et al.,
J. Anim. Sci. 2004. 82:2140–2147
1994) has resulted in increased soil concentrations of
Zn and Cu. Zinc and/or Cu accumulation in soil has
been implicated to reduced crop yields (Tucker, 1997;
Matsui and Yano, 1998).
1
Use of trade names in this publication does not imply endorsement
by the North Carolina Agric. Res. Service or criticism of similar
products not mentioned.
2
This research was supported by grants from the Animal Waste
Six-State Consortium and the North Carolina State Univ. Animal
and Poultry Waste Management Center, and by a gift from Chelated
Minerals Corp., Salt Lake City, UT. Appreciation is extended to Akey,
Lewisburg, OH, for supplying the vitamin premixes.
3
Correspondence—phone: 919-515-4008; fax: 919-515-4463; email: [email protected].
4
Present address: Elanco Animal Health, Cary, NC 27511-6614.
5
Present address: Dept. of Anim. Sci., Colorado State Univ., Fort
Collins 80523-1171.
Received September 26, 2003.
Accepted March 22, 2004.
2140
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2141
Trace mineral level and pig performance
A common practice within the swine industry is to
formulate diets with trace mineral concentrations that
exceed NRC (1998) recommendations. When trace minerals are fed in excess of animal requirements, more is
excreted in waste because of homeostatic mechanisms
that serve to regulate tissue concentrations of minerals
(Spears, 1996). Formulation of diets with mineral concentrations close to requirements would seem to be an
appropriate means of reducing concentrations of Zn and
Cu in waste without affecting animal performance.
The balance among minerals, in regard to dietary
concentrations relative to animal requirements, is an
important factor affecting mineral utilization. Antagonistic interactions can occur between Fe and Mn and
between Fe and Cu and Zn (O’Dell, 1997). Therefore,
reducing dietary Fe and Mn concentrations to levels
more in line with requirements may serve to minimize
Zn and Cu requirements. Another strategy for reducing
trace mineral concentrations in diets is inclusion of
mineral sources that may exhibit greater bioavailability than commonly used inorganic forms. Results have
been variable, but some studies have indicated that
chelated forms of trace minerals are more bioavailable
than inorganic forms (Spears, 1996).
The current study was conducted to determine the
effects of reducing supplemental concentrations of Zn,
Cu, Fe, and Mn on growth performance, mineral status,
and fecal mineral concentrations of gilts from weaning
through growing and development. A second objective
was to determine whether replacing 50% of the supplemental Zn, Cu, Fe, and Mn with chelated forms would
improve performance and/or decrease fecal mineral excretion.
Materials and Methods
Table 1. Ingredient composition of nursery diets (asfed basis)a,b
Item
Ingredient, %
Corn
Soybean meal, 48%
Dried whey
Fish meal
Porcine plasma
Blood meal
Poultry fat
Dicalcium phosphate
Calcium carbonate
Salt
Vitamin-mineral premixc
L-lysineⴢHCl
DL-methionine
Antibioticd
Calculated composition
CP, %
Lysine, %
Methionine + cystine, %
ME, kcal/kg
Ca, %
P, %
Complex
Corn-soybean
48.98
16.98
19.98
5.25
1.00
1.33
4.00
1.00
0.33
0.10
0.25
0.20
0.10
0.50
62.01
30.01
—
—
—
—
4.00
2.17
0.51
0.35
0.25
0.20
—
0.50
20.0
1.40
0.78
3,471
0.88
0.76
19.6
1.22
0.65
3,470
0.82
0.78
a
Diets were supplemented with either 1) control (25, 150, 180, and
60 mg/kg of supplemental Cu, Zn, Fe, and Mn, respectively, from
sulfate form(s); 2) reduced inorganic (5, 25, 25, and 10 mg/kg of
supplemental Cu, Zn, Fe, and Mn, respectively, from sulfate forms);
or 3) reduced chelated (5, 25, 25, and 10 mg/kg of supplemental
Cu, Zn, Fe, and Mn, respectively, from a combination (50% each) of
proteinate and sulfate forms) trace mineral mix.
b
Complex diet was fed from d 1 to 14 and corn-soybean diet was
fed from d 15 to 41 of the nursery phase.
c
Supplied the following per kilogram of complete diet: vitamin A,
11,000 IU; vitamin D3, 2,750 IU; vitamin E, 33 IU; vitamin K (as
menadione), 5.5 mg; vitamin B12, 0.033 mg; riboflavin, 6.6 mg; Dpantothenic acid, 26.4 mg; niacin, 88.0 mg; choline, 391 mg; thiamine,
2.2 mg; pyridoxine, 3.3 mg; folic acid, 0.66 mg; biotin, 0.11 mg; Se
(as NaSeO3), 0.3 mg; and I (as ethylenediamine dihydroiodide), 1.25
mg.
d
Supplied 55 mg of carbadox/kg of diet.
Experimental Design
Experimental procedures involving animals were approved by the North Carolina State University Animal
Care and Use Committee. Two hundred and sixteen
weanling crossbred gilts (6.65 ± 0.08 kg), 18 to 21 d of
age, were used in three trials (n = 72 gilts per trial).
The experimental design was similar for all trials. The
gilts were blocked by weight and randomly assigned
within a weight block to one of three treatments. Treatments consisted of 1) a control, 2) reduced inorganic
trace minerals, or 3) reduced chelated trace minerals.
Supplemental trace mineral concentrations in the control diets were formulated to be typical of those currently used in the swine industry. The control treatment during the nursery phase contained 25, 150, 180,
and 60 mg/kg of supplemental Cu, Zn, Fe, and Mn,
respectively. During the growing and finishing phase,
supplemental levels were reduced to 15, 100, 100, and
40 mg/kg for Cu, Zn, Fe, and Mn, respectively. The
reduced inorganic and reduced chelated treatments
were supplemented during all production phases with
5, 25, 25, and 10 mg/kg of supplemental Cu, Zn, Fe,
and Mn, respectively. Iron and Mn were decreased in
the reduced inorganic and reduced chelated treatments
because they are commonly supplemented in excess of
NRC (1998) recommendations, and because high dietary concentrations of these two minerals may increase Zn and/or Cu requirements. The control and reduced inorganic treatments supplied 100% of the supplemental Cu, Zn, Fe, and Mn from inorganic sulfate
forms. The reduced chelated treatment supplied 50%
of the supplemental Cu, Zn, Fe, and Mn in the form of
metal proteinates (Chelated Minerals Corp., Salt Lake
City, UT), with the remainder being supplied from inorganic sulfate forms.
Nursery Phase
Pigs were housed six pigs per pen (four replicate pens
per treatment per trial) in an environmentally controlled nursery. The temperature in the nursery was
30°C for the first week and was lowered by 1°C each
subsequent week. Ingredient composition of the nursery diets is shown in Table 1. A complex diet was fed
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Creech et al.
Table 2. Analyzed trace mineral concentrations in experimental diets
Treatment
Diet
Control
Reduced
inorganic
Item
Reduced
chelated
mg/kg of DM
Nursery (complex diet)
Copper
31.8
Zinc
229.6
Iron
325.8
Manganese
79.8
Nursery (corn-soy diet)
Copper
31.9
Zinc
234.0
Iron
354.8
Manganese
85.6
Growing
Copper
28.2
Zinc
178.7
Iron
317.5
Manganese
60.9
Gilt-developer
Copper
33.0
Zinc
167.0
Iron
411.5
Manganese
59.7
Table 3. Ingredient composition of growing and gilt-developer diets (as-fed basis)a,b
10.8
89.2
269.4
29.8
11.1
81.0
278.4
29.1
13.3
80.3
249.6
35.6
16.9
77.4
272.9
36.2
8.4
96.2
256.6
29.8
12.2
90.6
351.1
31.2
9.8
83.3
323.0
34.7
14.9
79.1
256.4
35.1
from d 1 to 14. A corn-soybean meal based diet was fed
from d 15 to 41. Diets were formulated to meet or exceed
NRC (1998) requirements. Analyzed trace mineral concentrations in diets are shown in Table 2. Feed and
water were provided ad libitum. Feed weighbacks were
taken weekly. Body weights were obtained on d 0, 14,
and 41 of the study.
Grower and Gilt-Developer Phases
At the end of the nursery phase, gilts were moved to
a curtain-sided finishing facility. Pigs in each pen from
the nursery remained together in the same pen
throughout the growing and gilt-developer phases. Ingredient composition of the growing and gilt-developer
diets is shown in Table 3. Diets were formulated to
meet or exceed NRC (1998) recommendations. Analyzed
Cu, Zn, Fe, and Mn concentrations in diets are presented in Table 2. Feed and water were provided ad
libitum.
Pigs were fed growing diets for 44 d. Gilt-developer
diets were fed for 59 d. Pigs averaged 59.5 kg BW when
they were switched to the gilt-developer diet.
Sample Collections and Analytical Procedures
Blood was collected on d 28 of the nursery phase from
three randomly selected pigs per replicate pen in each
trial. Two randomly selected pigs per replicate pen were
bled on d 41 and 54 of the growing and gilt-developer
phases, respectively. Samples were obtained via jugular
venipuncture into heparinized tubes designed for trace
mineral analysis (Vacutainer 9735, Becton, Dickinson,
Ingredient, %
Corn
Soybean meal, 48%
Poultry fat
Dicalcium phosphate
Calcium carbonate
Salt
Vitamin mineral premixc
L-LysineⴢHCl
Antibioticd
Calculated composition
CP, %
Lysine, %
Methionine + cystine, %
ME, kcal/kg
Ca, %
P, %
Growing
Gilt-developer
69.73
22.66
4.00
1.75
0.61
0.35
0.25
0.15
0.50
79.01
15.00
2.00
2.08
1.01
0.35
0.25
0.10
0.20
16.7
0.98
0.57
3,485
0.74
0.68
13.8
0.74
0.50
3,377
0.94
0.71
a
Diets were supplemented with either 1) control (15, 100, 100, and
40 mg/kg of supplemental Cu, Zn, Fe, and Mn, respectively, from
sulfate forms); 2) reduced inorganic (5, 25, 25, and 10 mg/kg of supplemental Cu, Zn, Fe, and Mn, respectively, from sulfate forms); or 3)
reduced chelated (5, 25, 25, and 10 mg/kg of supplemental Cu, Zn,
Fe, and Mn, respectively, from a combination (50% each) of proteinate
and sulfate forms) trace mineral mix.
b
Growing diet was fed for 44 d, and gilt-developer diet was fed for
59 d.
c
Supplied the following per kilogram of complete diet: vitamin A,
5,500 IU; vitamin D3, 1,320 IU; vitamin E, 19.8 IU; vitamin K (as
menadione), 2.2 mg; vitamin B12, 0.028 mg; D-pantothenic acid, 17.6
mg; niacin, 35.2 mg; choline, 95.6 mg; Se (as NaSeO3), 0.3 mg; and
I (as EDDI), 1.0 mg.
d
Supplied 55 mg of chlortetracycline/kg in the growing diet and 22
mg of chlortetracycline/kg in the finishing diet.
and Co., Rutherford, NJ). A sample of whole blood was
retained for hemoglobin determination. Plasma, obtained after centrifugation at 2,500 × g for 20 min, was
frozen and later analyzed for Cu and Zn concentration,
and alkaline phosphatase (AP) and ceruloplasmin activity.
Fecal grab samples were obtained by rectal palpation
from 12 pigs per treatment (three randomly selected
pigs per pen) in Trial 3 of the nursery phase for fecal
mineral analysis. Samples were taken from the same
pigs on d 38 at 0800, d 39 at 1500, and d 40 at 2100.
Fecal samples (two pigs per pen) were taken on d 33,
34, and 35 of the growing phase, and on d 56, 57, and
58 of the gilt-developer phase at the times specified
for the nursery phase. Fecal samples were composited
across times within a phase for Cu, Zn, Fe, and Mn
analysis.
A 100-␮L sample of whole blood was used for total
hemoglobin determination via the cyanomethemoglobin method (Sigma Chemical Co., 1995). Plasma was
diluted 1:3 (vol/vol) with deionized water and analyzed
for Cu and Zn concentration via flame atomic absorption spectrophotometry (model 5000, Perkin Elmer,
Norwalk, CT). Plasma ceruloplasmin activity was determined by the method described by Houchin (1958),
with results expressed as absorbance units. Plasma AP
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2143
Trace mineral level and pig performance
Table 4. Effect of trace mineral concentration and source on performance of nursery pigsa
Treatment
Item
Day 0 to 14
ADG, kg
ADFI, kg
G:F
Day 15 to 41
ADG, kg
ADFI, kg
G:F
Total nursery
Initial wt, kg
Final wt, kg
ADG, kg
ADFI, kg
G:F
Control
Reduced
inorganic
Reduced
chelated
SE
Significanceb
0.229
0.417
0.551
0.218
0.426
0.509
0.215
0.411
0.520
0.011
0.014
0.016
A†
0.556
1.056
0.535
0.548
1.068
0.518
0.551
0.998
0.554
0.012
0.033
0.009
B*
6.64
25.61
0.446
0.841
0.534
6.67
24.68
0.437
0.852
0.516
6.62
25.00
0.438
0.801
0.548
0.28
0.57
0.011
0.026
0.010
B*
†P < 0.10.
*P < 0.05.
a
Each mean represents results from three trials. Each trial consisted of four replicate pens (six pigs per
pen) per treatment. ADFI expressed on an as-fed basis.
b
A = control vs. reduced trace minerals; B = reduced inorganic vs. reduced chelated.
activity was determined using the method described by
Sigma Chemical Co. (1987).
Feed and fecal samples were dried and ground to
pass a 1-mm screen. Feed samples were taken at every
mixing from several bags per treatment. Samples were
then dried at 55°C for at least 48 h. Feed samples were
then ground, mixed evenly, and composited by treatment for the respective phase. Fecal samples were also
composited by pen following drying and grinding.
Feed and fecal samples were prepared for mineral
analysis by wet ashing using a microwave digestion
system (model MDS-81D, CEM Corp., Matthews, NC).
Approximately 0.5 g of sample (DM basis) was weighed
in duplicate and placed in teflon-lined digestion vessels.
Ten milliliters of trace mineral grade nitric acid was
added to the samples. Samples were digested for 30
min at room temperature and then sealed. The vessels
were placed in the microwave for 5 min at 50% power,
15 min at 70% power, and 10 min at 0 power. They
were then vented, and 2 mL of 30% hydrogen peroxide
was added. Vessels were placed in the microwave for
3 min at 50% power and 2 min at 0 power. Ashed samples were then brought up to volume in 25-mL volumetric flasks and analyzed for Cu, Zn, Fe, and Mn via flame
atomic absorption spectrophotometry.
Statistical Analyses
Data were analyzed using the GLM procedures of
SAS. The model included treatment, trial, block, and
trial × treatment interaction. When the trial by treatment interaction was significant, data were analyzed
by trial. When the trial × treatment interaction was
not significant (P > 0.10), only combined means are
presented. Pen was used as the experimental unit for
all variables. Single-df contrasts were used to compare
1) control vs. the two reduced treatments and; 2) reduced inorganic vs. reduced chelated treatment.
Results
Performance
Gain and ADFI were not affected by treatment during
the first 14 d of the nursery period when pigs were fed
a complex diet (Table 4). Gain:feed tended (P < 0.10)
to be higher for control pigs compared with those fed
reduced trace mineral diets during this period. However, ADG, ADFI, and G:F of control pigs did not differ
from those fed reduced trace minerals from d 15 to 41
or over the entire 41-d nursery period. Gain:feed was
higher (P < 0.05) in pigs fed the reduced chelated diet
from d 15 to 41 and over the total nursery period compared with pigs fed the reduced inorganic diet. The
improved G:F in pigs fed the reduced chelated diet was
due to feed intake being numerically lower (P = 0.16)
in this group compared with pigs in the reduced inorganic treatment.
Gain, ADFI, and gain:feed were not affected by treatment during the growing phase (Table 5). Pigs fed the
reduced trace mineral diets tended (P < 0.10) to have
higher ADG and ADFI than did control pigs during
the gilt-developer phase. Gain:feed did not differ across
treatments during the gilt-developer phase. When performance results were pooled over the growing and giltdeveloper phase, treatment did not affect ADG, ADFI
or gain:feed.
Mineral Status
Control pigs had higher (P < 0.01) plasma Zn concentrations than did those fed the reduced trace mineral
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Creech et al.
Table 5. Effect of trace mineral concentration and source on performance of growing and
developing giltsa
Treatment
Item
Control
Growing
ADG, kg
0.77
ADFI, kg
1.85
G:F
0.42
Developing
ADG, kg
0.82
ADFI, kg
2.60
G:F
0.31
Total growing-developing
Initial wt, kg
25.61
Final wt, kg
Growing
59.46
Developing
107.21
ADG, kg
0.78
ADFI, kg
2.28
G:F
0.34
Reduced
inorganic
Reduced
chelated
SE
0.76
1.87
0.41
0.78
1.86
0.42
0.02
0.05
0.01
0.84
2.68
0.31
0.84
2.72
0.31
0.01
0.04
0.01
24.68
25.00
0.57
59.10
108.14
0.80
2.32
0.34
59.81
108.98
0.80
2.34
0.34
1.41
1.69
0.01
0.04
0.01
Significanceb
A†
A†
†P < 0.10.
a
Each mean represents results from three trials. Each trial consisted of four replicate pens (six pigs per
pen) per treatment. ADFI expressed on an as-fed basis.
b
A = control vs. reduced trace minerals.
treatments on d 28 of the nursery phase (Table 6).
Plasma AP activity also was lower (P < 0.01) in pigs
fed the reduced inorganic and reduced chelated diets
compared with those fed the control diet during the
nursery phase. Plasma Cu concentrations tended (P <
0.10) to be higher in controls compared with pigs receiving reduced trace minerals, but plasma ceruloplasmin
was not affected by treatment during the nursery
phase. Hemoglobin concentration was lower (P < 0.05)
for the reduced inorganic compared with the reduced
chelated treatment. Trace mineral level did not affect
hemoglobin concentration.
On d 41 of the growing phase, plasma Zn concentration and AP activity continued to be higher (P < 0.01)
in controls than in pigs fed reduced trace mineral diets
(Table 6). Plasma Cu and hemoglobin concentrations
and ceruloplasmin activity did not differ across treatments during the growing phase.
Plasma Zn concentration in the gilt-developer phase
(d 54) was affected by a treatment × trial interaction
(P < 0.01; Table 6). Pigs fed the reduced trace mineral
treatments had lower (P < 0.05) plasma Zn concentrations than control pigs in Trial 3, but not in Trials 1
and 2. Plasma AP activity was not affected by trace
mineral level or source. During the gilt-developer
phase, plasma Cu was also affected by a treatment ×
trial interaction (P < 0.05). In Trial 1, control pigs had
higher (P < 0.05) plasma Cu concentrations than those
fed the reduced trace mineral diets. Plasma Cu was
higher (P < 0.05) in the reduced chelated treatment
compared with the reduced inorganic treatment in Trial
2. In Trial 3, plasma Cu was not affected by treatment.
Ceruloplasmin activity and hemoglobin concentration
were not affected by treatment during the gilt-developer phase.
Fecal Mineral Concentrations
Copper concentrations in fecal samples obtained during the nursery, growing, and gilt-developer phases
were higher (P < 0.01) for control pigs than for those
fed reduced Cu diets (Table 7). Pigs fed the reduced
inorganic diet had higher (P < 0.01) fecal Cu concentrations than pigs fed the reduced chelated diet during the
growing phase. Fecal Cu was affected by a treatment
× trial interaction (P < 0.01) in the gilt-developer period.
Control pigs had higher (P < 0.01) fecal Cu concentration than pigs fed the reduced trace mineral treatments
in all three trials. Copper concentrations in feces were
lower in pigs fed the reduced chelated diet compared
with those fed the reduced inorganic diet in Trials 2 (P
< 0.01) and 3 (P < 0.05), but not in Trial 1.
Fecal Zn concentrations were also much higher (P <
0.01) at all sampling times in controls than in pigs
fed the reduced trace minerals diets (Table 7). Pigs
receiving the reduced inorganic treatment had higher
(P < 0.01) fecal Zn concentrations than pigs fed the
reduced chelated treatment during the nursery phase.
Pigs fed the reduced chelated diet had lower fecal Fe
(P < 0.10) and Mn (P < 0.05) concentrations than pigs
fed the reduced inorganic diet during the nursery phase
(Table 7). Fecal Mn concentrations were higher (P <
0.05) at all sampling times in controls compared with
pigs fed reduced trace minerals. Control pigs had higher
(P < 0.01) fecal Fe concentrations than did those fed
the reduced trace mineral diets during the growing and
gilt-developer phases.
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Trace mineral level and pig performance
Table 6. Effect of trace mineral concentration and source on mineral status of gilts during
the nursery, growing, and gilt-developer phasesa
Treatment
Item
Nursery
Plasma Zn, mg/L
Plasma AP, U/Lc
Plasma Cu, mg/L
Plasma ceruloplasmin, absorbance
Hemoglobin, g/dL
Growing
Plasma Zn, mg/L
Plasma AP, U/Lc
Plasma Cu, mg/L
Plasma ceruloplasmin, absorbance
Hemoglobin, g/dL
Gilt-developer
Plasma Zn, mg/L
Trial 1
Trial 2
Trial 3
Plasma AP, U/Lc
Plasma Cu, mg/L
Trial 1
Trial 2
Trial 3
Plasma ceruloplasmin, absorbance
Hemoglobin, g/dL
Control
Reduced
inorganic
Reduced
chelated
SE
Significanceb
1.27
155.0
1.73
0.53
12.4
0.84
112.8
1.64
0.57
11.9
0.78
111.1
1.63
0.53
12.5
0.06
5.8
0.05
0.02
0.2
A**
A**
A†
0.94
92.6
2.01
0.69
13.0
0.68
80.4
1.91
0.68
12.8
0.70
70.7
1.95
0.67
13.2
0.04
4.2
0.07
0.02
0.3
A**
A**
1.10
1.05
0.90
1.34
79.4
2.04
2.33
1.93
1.86
0.72
12.9
0.94
1.00
0.91
0.90
77.5
1.94
2.07
1.88
1.89
0.67
12.5
0.84
0.91
0.90
0.72
66.3
1.94
1.87
2.02
1.92
0.70
12.8
0.06
0.11
0.03
0.14
4.8
0.05
0.07
0.04
0.09
0.02
0.06
A**C**
B*
A*
C*
A*
B*
†P < 0.10.
*P < 0.05.
**P < 0.01.
a
Each overall mean represents results from three trials. Each trial consisted of four replicate pens (two
or three pigs sampled per pen) per treatment. Blood samples were obtained on d 28, 41, and 54 of the
nursery, growing, and gilt-developer phases, respectively.
b
A = control vs. reduced trace minerals; B = reduced inorganic vs. reduced chelated; C = trial × treatment
interaction.
c
AP = alkaline phosphatase
Discussion
Reducing the amounts of Zn, Cu, Fe, and Mn supplemented to diets in the current study did not adversely
affect performance of gilts from weaning through development. Based on NRC (1998) recommendations and
analyzed mineral concentrations in the reduced trace
mineral diets (Table 3), Zn was most likely to be limiting. The Phase I nursery diet analyzed slightly lower
in Zn than the 100 mg Zn/kg recommended by NRC
(1998) for pigs weighing 5 to 10 kg. By analysis, growing
and gilt-developer diets contained approximately 150%
of current NRC (1998) recommended requirements for
Zn. Based on basal levels of Zn in previous studies with
corn-soybean meal-based diets, the growing and giltdeveloper diets were higher in Zn than anticipated,
considering that only 25 mg Zn/kg was supplemented
to the reduced diets (Pond and Jones, 1964; Hill and
Miller, 1983; Wedekind et al., 1994).
Previous studies indicate that Zn requirements of
growing and finishing pigs, based on growth, do not
exceed 50 mg/kg diet. Addition of Zn (50 or 500 mg Zn/
kg diet) to a corn-soybean meal-based diet containing
35 mg Zn/kg did not affect performance of growing and
finishing pigs (Hill and Miller, 1983). The addition of
Zn to a corn-soybean meal-based diet containing 23 to
27 mg of Zn/kg also did not improve performance of
pigs during the nursery or growing phase (Hill et al.,
1986). However, Zn supplementation of the control diet
did increase gain and feed intake during the finishing
phase of this study (Hill et al., 1986). Average daily
gain and feed intake were higher in gilts fed diets containing 53 or 80 mg of Zn/kg compared with those fed
22 mg of Zn/kg (Liptrap et al., 1970). Wedekind et al.
(1994) depleted Zn stores of pigs during the nursery
phase by feeding diets containing 37 to 42 mg of Zn/kg.
Zinc was then supplemented at 0, 5, 10, 20, 40, and 80
mg/kg in Exp. 1, and at 0, 7.5, and 15 mg/kg in Exp. 2
during the growing and finishing phases. The control
growing and finishing diets used in this study contained
32 and 27 mg of Zn/kg, respectively. Supplementation
of the control diets with Zn increased plasma and bone
Zn, but did not affect pig performance in either experiment.
In the current study, even though performance of
pigs was not affected by treatment, plasma Zn and AP
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2146
Creech et al.
Table 7. Effect of trace mineral concentration and source on fecal mineral concentrations
of gilts during the nursery, growing, and gilt-developer phases
Treatment
Control
Reduced
inorganic
Reduced
chelated
SE
Significancea
mg/kg of DM
Nurseryb
Copper
Zinc
Iron
Manganese
Growingc
Copper
Zinc
Iron
Manganese
Gilt-developerc
Copper
Trial 1
Trial 2
Trial 3
Zinc
Iron
Manganese
192
1,336
2,038
542
102
1,267
1,957
471
89
506
1,632
324
14
56
115
33
A**
A**B**
B†
A*B*
152
710
1,800
530
108
350
1,347
258
71
309
1,378
233
7
19
62
13
A**B**
A**
A**
A**
164
192
160
139
835
2,431
582
91
93
93
86
456
2,115
343
80
89
81
69
387
2,001
312
4
8
3
5
27
91
23
A**B*C**
A**
A**B**
A**B*
A**
A**
A**
†P < 0.10.
*P < 0.05.
**P < 0.01.
a
A = control vs. reduced trace minerals; B = reduced inorganic vs. reduced chelated; C = trial × treatment
interaction.
b
Each mean represents four pens (three pigs sampled per pen) from Trial 3. Fecal samples were obtained
on d 38, 39, and 40 and composited across days for analysis.
c
Each overall mean represents results from three trials. Each trial consisted of four replicate pens (two
pigs sampled per pen) per treatment. Fecal samples were obtained on d 33, 34, and 35 of the growing phase
and d 56, 57, and 58 of the gilt-developer phase and composited across days for analysis.
activity were lower in pigs fed reduced dietary Zn. Alkaline phosphatase activity and serum or plasma Zn have
been used as indicators of Zn status. However, the level
of circulating Zn in pigs necessary to maximize Zn dependent functions has not been defined. Gilts fed diets
containing 48 and 70 mg of Zn/kg had higher serum
AP activity and serum Zn concentrations than those
fed 29 mg of Zn/kg (Liptrap et al., 1970). Average daily
gain and ADFI were also lower in pigs fed the low Zn
diet (Liptrap et al., 1970). In agreement with the current study, Wedekind et al. (1994) observed that Zn
supplementation of diets containing 27 to 32 mg of Zn/
kg increased plasma Zn without affecting pig performance.
Bioavailability of Zn may be limited by high dietary
Ca. When Ca levels are increased in a diet with low
dietary Zn, the incidence of parakeratosis is increased
dramatically (Lewis et al., 1956; Luecke et al., 1956).
In the current study, Ca was supplied in the diets at
higher than NRC (1998) recommended requirements,
but no cases of parakeratosis were observed even in
pigs fed the reduced Zn diets. The nursery diets in the
current study contained approximately 120% and the
growing and gilt-developer diets contained 154 to 177%
of the NRC (1998) Ca requirements.
Iron and Mn are commonly present in swine diets in
excess of requirements. The reduced trace mineral diets
were supplemented with lower concentrations of Fe and
Mn to minimize any antagonistic effects of these minerals on Cu and Zn. Even in diets with reduced trace
minerals added, total dietary (supplemental plus basal
levels in the feedstuffs) Fe and Mn concentrations exceeded NRC (1998) recommendations by at least threefold (Table 3). Therefore, it is unlikely that either Fe
or Mn limited biochemical functions dependent on these
metals. Most commonly used feedstuffs are good
sources of Fe. For example, commercial dicalcium phosphate or defluorinated phosphate contains approximately 10,000 mg Fe/kg (Spears, 1996). In pigs, Fe from
defluorinated phosphate is at least 50% as available as
Fe from ferrous sulfate (Kornegay, 1972). Svajgr et al.
(1969) reported that practical corn-soybean meal-based
diets contain adequate Mn to meet requirements of
growing-finishing pigs.
The total Cu content of reduced trace mineral diets
in the current study exceeded NRC recommendations
in all phases of the study. Plasma Cu concentrations
and ceruloplasmin activity observed in pigs suggest
that the reduced-Cu diets provided adequate Cu. Dietary Cu requirements needed to maintain optimal metabolic functions in swine have received minimal attention. Hedges and Kornegay (1973) found that the Cu
requirement was no greater than 7 mg/kg in nursery
pigs fed high dietary Fe.
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Trace mineral level and pig performance
When minerals are supplemented in excess of the
animal’s requirement, more is excreted due to decreased efficiency of utilization for that mineral
(Spears, 1996). The current study clearly indicates that
reducing dietary Zn and Cu to concentrations closer
to nutritional requirements is an effective means of
reducing excretion of Zn and Cu in swine waste. Fecal
concentrations of Zn and Cu were reduced by approximately 50% in pigs fed reduced dietary Zn and Cu.
Decreasing Zn and Cu in swine waste is important because accumulation of these minerals in soil can lead
to toxicity in plants (Tucker, 1997; Matsui and Yano,
1998) and therefore potentially affect the sustainability
of large swine operations.
In the nursery phase, pigs fed 50% of their supplemental Zn, Cu, Fe, and Mn from chelated metal proteinates gained more efficiently than those fed similar concentrations of trace minerals solely from inorganic sulfate forms. Veum et al. (1995) also reported that
replacing a portion of the inorganic trace minerals with
proteinate forms improved feed efficiency in nursery
pigs. During the growing and gilt-developer phases, pig
performance was similar in pigs fed the reduced chelated treatment and those fed the reduced inorganic
treatment. However, fecal Cu and Zn concentrations
were lower or at least tended to be lower in pigs fed
the reduced chelated diet. Pigs fed proteinate forms of
Zn and Cu had higher liver Zn and Cu concentrations
than did pigs fed sulfate forms of these metals (Schiavon
et al., 2000). This suggests a higher utilization of Zn
and Cu from the proteinate compared with the sulfate sources.
Implications
The current study indicates that zinc and copper concentrations typically supplemented to gilt diets can be
greatly decreased without affecting pig performance
from weaning through development. Reducing supplemental concentrations of zinc and copper in pig diets
decreased fecal concentrations of copper and zinc by
approximately 50%. Lower excretion of zinc and copper
by swine will help prevent accumulation of these metals
in soils where swine waste is applied. Further studies
are needed to better define nutritional requirements of
pigs for zinc and copper.
Literature Cited
Hedges, J. D., and E. T. Kornegay. 1973. Interrelationships of dietary
copper and iron as measured by blood parameters, tissue stores
and feedlot performance of swine. J. Anim. Sci. 37:1147–1154.
Hill, D. A., E. R. Peo, Jr., A. J. Lewis, and J. D. Crenshaw. 1986.
Zinc-amino acid complexes for swine. J. Anim. Sci. 63:121–130.
2147
Hill, G. M., and E. R. Miller. 1983. Effect of dietary zinc levels on
the growth and development of the gilt. J. Anim. Sci. 57:106–113.
Houchin, O. B. 1958. A rapid colorimetric method for the quantitative
determination of copper oxidase activity (ceruloplasmin). Clin.
Chem. 4:519–523.
Kingery, W. L., C. W. Wood, D. P. Delaney, J. C. Williams, and G.
L. Mullins. 1994. Impact of long-term land application of broiler
litter on environmentally related soil properties. J. Environ.
Qual. 23:139–147.
Kornegay, E. T. 1972. Availability of iron contained in defluorinated
phosphate. J. Anim. Sci. 34:569–572.
Lewis, Jr., P. K., W. S. Hoekstra, R. H. Grummer, and P. H. Phillips.
1956. The effect of certain natural factors including calcium,
phosphorous and zinc on parakeratosis in swine. J. Anim. Sci.
15:741–751.
Liptrap, D. O., E. R. Miller, D. E. Ullrey, D. L. Whiteneck, B. L.
Schoepke, and R. W. Luecke. 1970. Sex influence on zinc requirement of developing swine. J. Anim. Sci. 30:736–741.
Luecke, R. W., J. A. Hoefer, W. G. Brammell, and F. Thorp, Jr. 1956.
Mineral interrelationships in parakeratosis of swine. J. Anim.
Sci. 347–351.
Matsui, T., and H. Yano. 1998. Formulation of low pollution feed
for animal production. Pages 110–119 in Proc. 8th World Conf.
Animal Prod. Symp. Ser. 1, Seoul, Korea.
Mueller, J. P., J. P. Zublena, M. H. Poore, J. C. Barker, and J. T. Green.
1994. Managing pasture and hay fields receiving nutrients from
anaerobic swine waste lagoons. N C Coop. Ext. Service, AG-506.
NRC. 1998. Nutrition Requirement of Swine. 10th rev. ed. Natl. Acad.
Press, Washington, DC.
O’Dell, B. L. 1997. Mineral-ion interaction as assessed by bioavailability and ion channel function. Pages 641–659 in Handbook of
Nutritionally Essential Mineral Elements. B. L. O’Dell, and R.
A. Sunde, ed. Marcel Dekker Inc., New York.
Pond, W. G., and J. R. Jones. 1964. Effect of level of zinc in highcalcium diets on pigs from weaning through one reproductive
cycle and on subsequent growth of their offspring. J. Anim. Sci.
23:1057–1060.
Schiavon, S., L. Bailoni, M. Ramanzin, R. Vincenzi, A. Simonetto,
and G. Bittante. 2000. Effect of proteinate or sulfate mineral
sources on trace elements in blood and liver of piglets. Anim.
Sci. 71:131–139.
Sigma. 1987. The quantitative kinetic determination of alkaline phosphatase (AP) in serum or plasma at 405 nm. Tech. Bull. No.
246. Sigma Chemical, St. Louis, MO.
Sigma. 1995. Total hemoglobin:Quantitative, colorimetric determination of whole blood at 530–550 nm. Tech. Bull. No. 525. rev. ed.
Sigma Chemical, St. Louis, MO.
Spears, J. W. 1996. Optimizing mineral levels and sources for farm
animals. Pages 259–275 in Nutrient Management of Food Animals to Enhance and Protect the Environment. E. T. Kornegay,
ed. CRC Press, Inc., Boca Raton, FL.
Svajgr, A. J., E. R. Peo, Jr., and P. E. Vipperman, Jr. 1969. Effects
of dietary levels of manganese and magnesium on performance
of growing-finishing swine raised in confinement and on pasture.
J. Anim. Sci. 29:439–443.
Tucker, M. R. 1997. Experiences with metal toxicities in North Carolina. Pages 97–100 in Proc. Soil Sci. Soc. Soil Sci. Soc. of North
Carolina, Raleigh.
Veum, T. L., D. W. Bollinger, M. Ellersieck, and J. T. Halley. 1995.
Proteinated trace minerals and condensed fish protein digest in
weanling pig diets. J. Anim. Sci. 73(Suppl. 1):308. (Abstr.)
Wedekind, K. J., A. J. Lewis, M. A. Giesemann, and P. S. Miller.
1994. Bioavailability of zinc from inorganic and organic sources
for pigs fed corn-soybean meal diets. J. Anim. Sci. 72:2681–2689.
Downloaded from jas.fass.org by on December 10, 2009.
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